The Raptor's rear leaf springs and blocks are its only weak point. They cause the rear to stutter and chatter over small bumps and have spring wrap. Lots of spring wrap. Deaver Spring builds these Raptor replacement leaf packs that have 11 thin leaves and one rebound leaf to reduce (or completely negate) axle wrap. The Deaver springs are direct replacements for the OE leaf packs and delete the OE lift block. They come with everything needed for the swap, including new 18mm front eye bolts, bushings, and U-bolts. The new 18mm front eye bolts are a nice touch. Ford installed the eye bolts before the gas tank and exhaust. To remove the front eye bolts, the gas tank and muffler need to be dropped. Deaver supplied new OE bolts so the original eye bolts can be cut off and replaced with their new bolts from the outside of the frame - much easier than dropping the tank and muffler.